I have hopefully sourced an m90 engine block, which has a 93.5mm bore and 84mm stroke, compared to the 92mm bore and 86mm stroke of a later m30 engine.
I have to ideas with what to do with the m90 block.
Option 1 - M90 block, crank, rods, pistons and headgasket with m30 oil pump, pickup, sump, timing covers, ignition, loom, ported inlet and uprated cam. This should give a much nicer reving engine than a stock m30 due to the shorter stroke.
Option 2 - M90 block, rods and pistons with m30 crank and other bits as above giving a 3.6ish litre displacement, and alot of power hopefully.
Does anyone know more about the feasibility of option 2? I'd be interested to hear your input.
Thanks,
Theo
M30 increased displacement
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DRIFTBOY
- E30 Zone Addict
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Great find Theo, as we have already discussed your discovery! 
I like the idea of making an M30 3.6, as they are actualy a 3.43 to start with.
It seems this is quite popular in America.
Well done for sourcing an engine, I've looked but not found anything.
Did you read about the 'L' embossed on the inlet side of the block? That's how to tell if it's an M90 block.
If the blocks are the same height then it's easy, use M30 crank and rods if they fit the M90 pistons, otherwise machining work will need to be done.
I'm interested to see how you get on with this, which ever option you choose.
I like the idea of making an M30 3.6, as they are actualy a 3.43 to start with.
It seems this is quite popular in America.
Well done for sourcing an engine, I've looked but not found anything.
Did you read about the 'L' embossed on the inlet side of the block? That's how to tell if it's an M90 block.
If the blocks are the same height then it's easy, use M30 crank and rods if they fit the M90 pistons, otherwise machining work will need to be done.
I'm interested to see how you get on with this, which ever option you choose.
Jeremy Clarkson wrote:...but it drives the front wheels. Theee wrooong wheels!
da4x4turbo wrote:I raced a vivaro on the motorway once in a 318is.... and lost!!!
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Theo
- Old Skooler
- Posts: 10735
- Joined: Wed Jun 01, 2005 11:00 pm
- Location: Kent
Yeah, later m30b35's are 3430cc, but the early engines with an m90 block were 3453cc (woo another 23cc).
I read all about how to identify an m90, not sure if the L is still on the block i'm getting, but it has 93.5cm bores so thats good enough for me.
The M30 and M90 used the same rods, so there's no issue there at least. Whats the best way to accurately measure the blocks? Get the piston at TDC and measure where it is relative to the top of the block?
I read all about how to identify an m90, not sure if the L is still on the block i'm getting, but it has 93.5cm bores so thats good enough for me.
The M30 and M90 used the same rods, so there's no issue there at least. Whats the best way to accurately measure the blocks? Get the piston at TDC and measure where it is relative to the top of the block?